Continuous sheet print control apparatus and method to set discharged sheet surface orientation

ABSTRACT

An apparatus to cause a print unit to print data on a continuous sheet includes a reception, a determination, and a print control unit. The determination unit determines whether the received data is to be printed on a single or both sides of the continuous sheet. The print unit prints the data in a manner such that a front surface orientation of each duplex printing discharged sheet when discharged after having been printed on its both sides and a front surface orientation of each simplex printing discharged sheet when discharged after having been printed on its single side is the same. When simplex printing is performed, each page to be arranged on the front surface of a discharged sheet of simplex printing is printed first. When duplex printing is performed, each page to be arranged on the back surface of a discharged sheet of duplex printing is printed first.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/960,400, filed on Dec. 3, 2010, which claims priority fromJapanese Patent Application No. 2010-082798, filed Mar. 31, 2010, all ofwhich are hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a print control apparatus and methodfor use in printing that employs a continuous sheet.

2. Description of the Related Art

There is an apparatus of printing images on both sides of a continuoussheet, such as a roll of paper, by printing data on a single side of thecontinuous sheet introduced to a print unit, cutting the continuoussheet, temporarily winding the cut continuous sheet, reintroducing thecut continuous sheet to the print unit, and printing data on theopposite side (see, for example, Japanese Patent Laid-Open No.11-249346). For such a printing apparatus, to enhance the efficiency ofprinting, images of a plurality of pages are successively printed on asingle side, and after the completion of printing the images of allpages on the single side, an image is printed on the opposite side.

For printing with such a procedure, the sequence of pages is determinedsuch that the printing sequence is the above-described sequence. Theprinted sheet with the image formed on both sides is cut by a cutterinto sheets, and the sheets are stacked in succession with their frontsides facing downward (face-down discharged). In contrast, for printingon only a single side of a sheet, because it is not necessary to performprinting on the back side of the sheet, the printed sheet with theimages formed on its front side is cut by a cutter into sheets, and thesheets are stacked in succession with their front sides facing upward(face-up discharged).

Accordingly, for printing of a continuous sheet in such a way, simplexprinting and duplex printing have different sequences of sheetsarranged. This complicates checking the printed sheets when a usercollects them.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, an apparatus capable ofcausing a print unit to print data on a continuous sheet includes areception unit configured to receive data of a plurality of pages to beprinted by the print unit, a determination unit configured to determinewhether the data of the plurality of pages received by the receptionunit is to be printed on a single side of the continuous sheet or onboth sides of the continuous sheet, and a print control unit configuredto cause the print unit to print the data of the plurality of pagesreceived by the reception unit on the continuous sheet in a manner suchthat an orientation of a front surface of each discharged sheet ofduplex printing from the continuous sheet in a case of being dischargedafter having been printed on its both sides and an orientation of afront surface of each discharged sheet of simplex printing from thecontinuous sheet in a case of being discharged after having been printedon its single side is the same, wherein each discharged sheet of duplexprinting and of simplex printing have the front surface and a backsurface, wherein, in a case where the determination unit determines thatsimplex printing is to be performed, the print control unit causes theprint unit to print each page to be arranged on the front surface of adischarged sheet of simplex printing first, and wherein, in a case wherethe determination unit determines that duplex printing is to beperformed, the print control unit causes the print unit to print eachpage to be arranged on the back surface of a discharged sheet of duplexprinting first.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a configuration of an image forming apparatusaccording to an embodiment of the present invention.

FIG. 2 is a block diagram of a configuration for use in controlling theimage forming apparatus illustrated in FIG. 1.

FIGS. 3A and 3B illustrate arrangements of images for simplex printingand duplex printing.

FIG. 4 is a flowchart of a process occurring when images are printed ona continuous sheet.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention are described below with referenceto the drawings. Relative arrangement of elements of an apparatus andthe shape of the apparatus used in the embodiments are illustrated asmerely an example. The embodiments are not limited to the illustratedones.

FIG. 1 illustrates a schematic configuration of an image formingapparatus that is an example of a print control apparatus according tothe present embodiment. For the image forming apparatus in FIG. 1, onlycomponents having a printing function of printing data received from anexternal apparatus are illustrated. However, the image forming apparatusis not limited to the illustrated one. For example, the image formingapparatus can be an apparatus functioning as a copier that furtherincludes a scanner for reading an image on a document or a multifunctionapparatus that has other additional functions.

An example that employs a rolled sheet as a recording material(recording medium or recording sheet) that is to be subjected toprinting is described. This rolled sheet is an example of a continuoussheet. However, an example other than such a rolled sheet can also beused as long as it is a long continuous sheet that allows data of aplurality of pages to be printed on the same side without being cutbefore the completion of the printing. A continuous sheet may beautomatically cut by the image forming apparatus or manually cut by auser providing an instruction. A recording material can be made ofvarious kinds of materials, including paper, as long as data can beprinted thereon. The image forming apparatus can print data on not onlya continuous sheet but also a sheet that has been cut into a specificsize previously.

A printing process is not limited to the inkjet process employing liquidink for image printing, which is described below. The printing processmay use solid ink as a recording agent to be applied to a recordingmaterial. Various processes can be used as the printing process. Forexample, the electrophotographic process employing toner,dye-sublimation process, thermal transfer process, and dot impactprocess can be used. Additionally, the printing process can support bothcolor recording employing recording agents corresponding to multiplecolors and monochrome recording employing only black, including gray.Moreover, not only a visible image but also an invisible image or animage difficult to visually identify may be printed. Other than atypical image, for example, a wiring pattern, physical pattern inproduction of parts, and a DNA base sequence may be printed. That is,various types of recording apparatuses can be used as long as they canapply a recording agent to a recording material. When the image formingapparatus illustrated in FIG. 1 controls operations of printing inresponse to an instruction from an external apparatus connected to theimage forming apparatus, this external apparatus is a print controlapparatus.

FIG. 1 is a cross-sectional view that illustrates a schematicconfiguration in general of an image forming apparatus that employs, asa recording material, a rolled sheet (continuous sheet that is longerthan a printing unit (one page) in the direction of conveyance). Theimage forming apparatus includes components 101 to 115 arranged in asingle housing. These components may alternatively be arranged in aplurality of housings.

A control unit 108 includes a controller, an output device, and acontrol unit that are incorporated therein. The controller includes acentral processing unit (CPU) or microprocessor unit (MPU). The outputdevice outputs user interface information and can be a generator thatgenerates display information and acoustical information. The controlunit includes various input/output (I/O) interfaces. The control unit108 excises control over the image forming apparatus.

Two units for holding and supplying a rolled sheet are an upper sheetcassette 101 a and a lower sheet cassette 101 b. A user attaches arolled sheet (hereinafter referred to as a sheet) to a magazine and thenloads it to the main body of the image forming apparatus. A sheet drawnout of the upper sheet cassette 101 a and that of the lower sheetcassette 101 b are conveyed along the directions “a” and “b” illustratedin the drawing, respectively. The sheet from each of the cassettestravels along the direction “c” illustrated in the drawing and reaches aconveying unit 102. The conveying unit 102 conveys the sheet duringprinting along the direction “d” illustrated in the drawing(substantially horizontal direction) while causing the sheet to passthrough a plurality of rollers 104. To switch a sheet supplier from afirst sheet cassette to a second sheet cassette, a drawn sheet is rolledback to the first cassette and a new sheet is supplied from the secondcassette.

A head unit 105 is arranged above the conveying unit 102 so as to faceit. In the head unit 105, a plurality of independent print heads 106corresponding to the number of colors (seven for the present embodiment)are held along the direction of conveyance of a sheet. For the presentembodiment, the seven print heads 106 correspond to seven colors of cyan(C), magenta (M), yellow (Y), light cyan (LC), light magenta (LM), gray(G), and black (K). However, colors other than these colors may be used,or any or any combination of those colors may be used.

The image forming apparatus forms an image on a sheet by ejecting inkfrom the print heads 106 in synchronization with conveyance of the sheetby the conveying unit 102. The print heads 106 are arranged at locationswhere droplets ejected therefrom do not overlap the rollers 104. Ink isejected directly to a sheet. However, other ways may be used. Forexample, ink may alternatively be applied to an intermediate transfermember, and the applied ink is provided to a sheet, thus forming animage on the sheet.

A unit for printing according to the present embodiment is configured toinclude the conveying unit 102, head unit 105, and print heads 106.

Independent ink tanks 109 store their respective inks corresponding tocolors. Each of the ink tanks 109 supplies the ink through a tube to asub tank provided to the corresponding color. The ink is supplied fromthe sub tank to the corresponding print head 106 through a tube. For theprint heads 106, line heads corresponding to the colors (seven colorsfor the present embodiment) are arranged along the direction “d” ofconveyance of a sheet during printing. The line heads may be made of asingle seamless nozzle chip or may alternatively be formed as separatednozzle chips regularly arranged in one row or in a staggeredconfiguration. For the present embodiment, a head in which nozzles arearranged in a range that covers the width of a printing region of asheet at a usable maximum size, which is a so-called full-multi head, isemployed. The inkjet process ejecting ink from the nozzles may usevarious systems, such as a system employing a heating element, thatemploying a piezoelectric element, that employing an electrostaticelement, and that employing a micro-electric-mechanical system (MEMS)element. Ink is ejected from the nozzles of each head in response toprint data. The time of ejecting ink is determined based on an outputsignal of a conveyance encoder 103.

After an image is formed on a sheet, the sheet is conveyed from theconveying unit 102 to a scanner unit 107. The scanner unit 107 checkswhether there is no problem in a formed image by optically reading theformed image or a special pattern on the sheet and checks the conditionof the apparatus, including an ink ejection condition. A method ofchecking a formed image may be examining an ink ejection condition byreading a pattern for use in checking the condition of a head ordetermining whether printing is successful or not by comparing theformed image with an original image. An appropriate checking method maybe selected from among various ones.

A sheet is conveyed from the vicinity of the scanner unit 107 along thedirection “e” and is introduced into a cutter unit 110. The cutter unit110 cuts the sheet by a specific printing unit length. The specificprinting unit length varies depending on the size of an image to beprinted. For example, for a photograph having a Japanese regularphotograph print size (approximately 89×127 mm), the length in thedirection of conveyance is approximately 135 mm; for A4 size, the lengthin the direction of conveyance is approximately 297 mm. For simplexprinting, the cutter unit 110 typically cuts a sheet on a page basis;however, it may not cut a sheet on a page basis depending on the contentof a print job. For duplex printing, after images are successivelyprinted on a first side (a side on which printing is first performed) ofa sheet for a specific length without the sheet being cut on a pagebasis, the cutter unit 110 cuts the sheet on a page basis when an imageis printed on a second side (a side that is opposite to the first sideand is subsequently subjected to printing). However, for simplexprinting or printing on a back side in duplex printing, the cutter unit110 may not cut a sheet for each image. For example, the cutter unit 110may not cut a sheet until a specific length of the sheet is conveyed,and the sheet may be cut for each image of one page by another cutterdevice in response to a manual operation. If it is necessary to cut asheet in its width direction, another cutter device cuts it.

A sheet from the cutter unit 110 is conveyed along the direction “f”illustrated in the drawing to a back-side print unit 111. The back-sideprint unit 111 is a unit for printing specific information on the backside of a sheet when only a single side of the sheet is subjected toprinting. Examples of information printed on the back side of a sheetinclude a character, symbol, and code (e.g., order management number)corresponding to each print image. For printing images for a print jobof duplex printing using the print heads 106, the back-side print unit111 prints the above-described information on an area other than aprinting region where the images are printed using the print heads 106.The back-side print unit 111 can use stamping employing a recordingagent, thermal transferring, and ink jetting.

A sheet passing through the back-side print unit 111 is conveyed to adrying unit 112. The drying unit 112 is a unit that heats a sheetpassing therethrough along the direction “g” illustrated in the drawingwith a warm current of air (heated gas (air)) to dry the sheet with inkbeing applied thereon in a short period of time. Various drying methodsother than a method employing a warm current of air can also be used.For example, drying employing a cool current of air, that by heating bya heater, natural drying only by letting the sheet wait, drying byradiation with electromagnetic waves, such as ultraviolet light, canalso be used. The sheets cut into specific printing unit lengths passthrough the drying unit 112 one by one and are conveyed along thedirection “h” illustrated in the drawing to a sorting unit 114.

The sorting unit 114 includes a plurality of trays (18 for the presentembodiment) and selectively uses a tray for receiving a discharged sheetdepending on, for example, its printing unit length. The trays haveindividual tray numbers. The sorting unit 114 discharges each of thesheets passing therethrough along the direction “i” illustrated in thedrawing to a tray associated with the tray number set for each printimage while checking by a sensor provided to each tray whether the trayis available, whether it is full of sheets, or other conditions. A trayfor receiving a discharged cut sheet to be discharged can bespecifically set by a source (host apparatus) of a print job or can befreely set by the image forming apparatus at an available tray. Themaximum number of sheets that can be discharged to a single tray ispreviously set. For a print job exceeding the previously set maximumnumber of sheets, the sheets are discharged to a plurality of trays. Themaximum number of sheets and the size and type of a sheet that can bedischarged to a tray vary with the size (type) of the tray. In FIG. 1,trays arranged substantially vertically (from top to bottom), which arehereinafter referred to as large trays, can receive both a sheet with alarge size (e.g., A4, which is larger than, for example, a Japaneseregular photograph size of approximately 89×127 mm) and a sheet with asmall size (e.g., approximately 89×127 mm). Trays arranged substantiallyhorizontally (from left to right), which are hereinafter referred to assmall trays, can receive a sheet with a small size (e.g., approximately89×127 mm), but cannot receive a sheet with a large size. The number ofsheets that can be discharged to each of the large trays is greater thanthat to each of the small trays.

A condition, such as discharging sheets in progress or completion ofdischarging, can be identified by a user through an indicator, which canemploy a light-emitting diode (LED), for example. Specifically, forinstance, each of the trays is provided with a plurality of LEDsemitting different color beams, and a user can be notified of variousconditions of the tray by seeing the color of an illuminating LED or thestate of illumination of the LED, such as lighting up or blinking.Priorities can be assigned to the trays, and the image forming apparatuscan assign available trays (empty of sheets) in sequence to adestination of discharging sheets according to the priorities. Thedefault is that, for the large trays, higher trays have higherpriorities and, for the small trays, trays at more left side have higherpriorities. The large trays have higher priorities than those for thesmall trays. A higher priority may be assigned in advance to a tray fromwhich a user can take a sheet easily. The priorities can be changed byan operation from a user.

A sheet winding unit 113 winds a sheet that has images formed on itsfirst side without being cut on a page basis. For duplex printing, thecutter unit 110 does not cut a sheet that has images formed on its firstside on a page basis and cuts the sheet after the last image ofsuccessive images printed on the first side has passed therethrough. Thesheet having the images formed on its first side moves along thedirection “j” illustrated in the drawing and is wound by the sheetwinding unit 113. The sheet cut by the cutter unit 110 after thecompletion of printing the images of a series of pages on the first sideis conveyed again from the sheet winding unit 113 such that the sideopposite to the first side is used as a side on which an image can beprinted. That is, the sheet winding unit 113 reverses a side of thesheet having images formed on its first side that faces the print heads106 and conveys it again along the direction “k” illustrated in thedrawing. At this time, a part of the sheet at which the sheet has beencut is first conveyed. Conveyance in such a way enables printing imageson the side (second side) opposite to the first side. For normal simplexprinting, a sheet on which images are printed is conveyed to the sortingunit 114 without being wound by the sheet winding unit 113.

In this way, for duplex printing, a sheet is wound by the use of thesheet winding unit 113, the sheet is reversed, and then the second sideis subjected to printing. Therefore, if printing is performed inascending order of page numbers, the orientation of a sheet surface andthe sequence of sheets arranged in a discharge to the sorting unit 114are different from those for simplex printing. That is, for simplexprinting, because reversal of a sheet using the sheet winding unit 113does not occur, a sheet with the image of the first page being printedthereon is discharged in a state where the image of the first page facesdownward. For a single print job having a plurality of pages, a sheet ofthe first page is first discharged to a tray and subsequent pages aredischarged in succession, and they are stacked. This type of dischargingis called face-down discharging. In contrast, for duplex printing,because a sheet is reversed using the sheet winding unit 113, a sheet onwhich the image of the first page is printed is discharged in a statewhere the image of the first page faces upward. For a single print jobrequiring outputting a plurality of sheets, a sheet containing the lastpage is first discharged to a tray, subsequent pages of sheets aredischarged in descending page order in succession and stacked, and asheet on which the image of the first page is printed is finallydischarged. This type of discharging is called face-up discharging. Incontrast to this, for the present embodiment, to avoid the orientationof a surface of a discharged sheet that faces a tray (hereinafter alsoreferred to as a discharge surface) and the sequence of sheets arrangedfrom differing between simplex printing and duplex printing, differentprinting sequences are used in simplex printing and duplex printing. Thedetails are described below.

An operating unit 115 is a unit through which a user inputs variousoperations or is notified of various kinds of information. For example,a user can identify, on an order basis, a printing condition, such aswhich tray a sheet having an image specified by a user being printedthereon is stacked or whether the image is being printed or has alreadybeen printed. In addition, a user can manipulate the operating unit 115to identify various statuses of the apparatus, such as the amount ofremaining ink and the amount of remaining sheet, or to provide aninstruction to conduct maintenance for the apparatus, such as headcleaning.

FIG. 2 is a block diagram of a configuration for use in controlling theimage forming apparatus illustrated in FIG. 1. An image formingapparatus 200 is the image forming apparatus illustrated in FIG. 1. Theillustrated configuration is merely an example, and various changes canbe made.

The control unit 108 includes a CPU 201, a read-only memory (ROM) 202, arandom-access memory (RAM) 203, an image processing unit 207, an enginecontrol unit 208, and a scanner control unit 209. The control unit 108is connected to a hard disk drive (HDD) 204, an operating unit 206, andan external interface (I/F) 205 through a system bus 210.

The CPU 201 is a central processing unit having a microprocessor(microcomputer) form and is included in the control unit 108 illustratedin FIG. 1. The CPU 201 executes a program and exercises control overoperations of the image forming apparatus 200 in response to activationof hardware. The ROM 202 stores programs executable by the CPU 201 andfixed data necessary to various operations of the image formingapparatus 200. The RAM 203 is used as a work area of the CPU 201, as atemporary storage region for various kinds of received data, and storesvarious kinds of data of settings. The HDD 204 can store, in an internalhard disk, programs executable by the CPU 201, print data, andinformation on settings necessary to various operations of the imageforming apparatus 200 and can read any of them therefrom. Instead of theHDD 204, other mass-storage devices may be employed.

The operating unit 206 can include a hard key and a touch panel for usein inputting various operations from a user and a display section forproviding (notifying) various kinds of information to a user andcorresponds to the operating unit 115 illustrated in FIG. 1. Informationcan be provided to a user by the use of an output sound (e.g., buzzersound or voice) based on sound information from a sound generationdevice.

The image processing unit 207 develops (converts) print data (e.g., datarepresented by page description language) handled by the image formingapparatus 200 into image data (bitmap image) and performs imageprocessing. For example, the image processing unit 207 converts a colorspace (e.g., YCbCr) of image data contained in input print data into astandard RGB color space (e.g., sRGB). Various kinds of image processingare performed on image data; examples thereof include resolutionconversion into an effective number of pixels (with that number, theimage forming apparatus 200 can perform printing thereon), imageanalysis, and image correction. Image data obtained through such imageprocessing is stored in the RAM 203 or HDD 204.

The engine control unit 208 controls processing of printing an imagebased on print data on a sheet in response to a control command from theCPU 201 or other elements. For example, the engine control unit 208provides the print head 106 associated with each color with aninstruction to discharge ink, sets discharge timing for use in adjustingthe position of a dot on a recording medium (ink landing position), andcarries out adjustment based on an obtained head driven state. Theengine control unit 208 also controls driving of the print head inaccordance with print data, causes the print head to discharge ink toform an image on a sheet. In addition, the engine control unit 208provides an instruction to drive an extracting roller for extracting asheet from a cassette and controls a conveying roller for conveying theextracted sheet, such as providing an instruction to drive the conveyingroller and obtaining a rotation state of the conveying roller, thusconveying the sheet at an appropriate speed and through an appropriatepath and stopping the sheet.

The scanner control unit 209 controls an image sensor in response to acontrol command received from the CPU 201 or other elements, reads animage on a sheet, obtains analog luminance data for red (R), green (G),and blue (B), and converts the analog data into digital data. Examplesof the image sensor can include a charge-coupled device (CCD) imagesensor and a complementary metal-oxide semiconductor (CMOS) imagesensor. The image sensor can also be a linear image sensor or an areaimage sensor. The scanner control unit 209 provides an instruction todrive the image sensor, obtains a state of the image sensor based on thedriving, analyzes luminance data obtained from the image sensor, anddetects non-discharging of ink from the print head 106 and the positionof cutting the sheet. A sheet whose image is determined by the scannercontrol unit 209 to have been correctly printed is subjected toprocessing of drying ink on the sheet. Then, the sheet is discharged toa specified tray of the sorting unit 114.

A host apparatus 211 corresponds to the above-described externalapparatus. The host apparatus 211 is externally connected to the imageforming apparatus 200 and is a source of supplying image data to beprinted by the image forming apparatus 200. The host apparatus 211issues orders of various print jobs.

The host apparatus 211 may be achieved by a general-purpose personalcomputer (PC) or other types of data supply apparatus. An example of theother types of data supply apparatus can be an image capture apparatusfor capturing an image and generating image data. Examples of the imagecapture apparatus can include a reader (scanner) that reads an image ona document and generates image data and a film scanner that readsinformation from a negative film or a positive film and generates imagedata. Other examples of the image capture apparatus can include adigital camera that obtains a still image and generates digital imagedata and a digital video camera that picks up movie and generates movieimage data. Alternatively, an image file may be read from a photographicstorage placed on a network or from a mobile memory detachably insertedinto a socket of the image forming apparatus 200, image data may begenerated therefrom, and the data may be printed. In place of ageneral-purpose PC, various data supply apparatuses can be used. Forexample, a terminal dedicated to the image forming apparatus may beused. The data supply apparatus may be a component of the image formingapparatus, or alternatively, may be a different apparatus externallyconnected to the image forming apparatus. When the host apparatus 211 isa PC, an operating system (OS), application software for generatingimage data, and a printer driver for use by the image forming apparatus200 are installed in storage of the PC. The printer driver controls theimage forming apparatus 200 and converts image data supplied from theapplication software into a form that can be handled by the imageforming apparatus 200 to generate print data. Conversion of print datainto image data may also be carried out by the host apparatus 211 beforethe data is supplied to the image forming apparatus 200. Not all of theabove-described processing may be achieved by software; part or allthereof may be achieved by hardware, such as an application-specificintegrated circuit (ASIC). Image data, other commands, status signalssupplied from the host apparatus 211 may be exchanged with the imageforming apparatus 200 through the external I/F 205. The external I/F 205may be a local I/F or a network I/F. The external I/F 205 may beachieved by cable connection or wireless connection.

The above-described elements within the image forming apparatus 200 areconnected through the system bus 210 and can communicate with oneanother.

For the above-described example, the single CPU 201 controls all of thecomponents within the image forming apparatus 200 illustrated in FIG. 2.However, other configurations may be used. That is, some of thefunctional blocks may have own CPUs, and the CPUs may individuallycontrol their respective blocks. Various forms can be used for thefunctional blocks. For example, the functional blocks may be dividedinto individual processing units or control units such that they haveshare different from that in the configuration illustrated in FIG. 2, orsome of them may be integrated. A direct memory access controller (DMAC)may also be used in reading data from memory.

FIGS. 3A and 3B illustrate a case where the image forming apparatus 200performs printing on only a single side of a rolled sheet and a casewhere it performs printing on both side thereof. The images of pagesillustrated in FIGS. 3A and 3B are arranged without a gap. However, amargin may be provided between pages. That is, in the following,successively printing a plurality of images contains a case where amargin is provided between images and indicates continuing printing onthe same side (without cutting the sheet for the first side of duplexprinting). In FIGS. 3A and 3B, an image of one page is arranged on eachside of one sheet to be discharged to a tray. However, images of aplurality of pages may be arranged on the same side. In both the casesillustrated in FIGS. 3A and 3B, seven sheets are discharged on a tray.For duplex printing, among a series of sheets discharged to a tray, asheet on which only its single side is subjected to printing may exist.However, for the illustrated case, both sides of all the sheets aresubjected to printing.

For printing on only a single side of a sheet, first, print data ofseven pages is input from the host apparatus 211 to the image formingapparatus 200 through the external I/F 205 together with specificationinformation for simplex printing in the sequence of page numbers 1, 2,3, . . . , and 7. When face-down discharging is set in the image formingapparatus 200 as discharging a printed sheet to a tray, the printingsequence is the same as the inputting sequence, i.e., printing startsfrom page 1. The printing sequence in this case is illustrated in FIG.3A. With this, sheets are discharged face down, and pages are arrangedin ascending order, thus enabling the sheets to be discharged withoutsorting by a user.

In contrast, for printing on both side of a sheet, first, print data of14 pages is input from the host apparatus 211 to the image formingapparatus 200 through the external I/F 205 together with specificationinformation for duplex printing in the sequence of page numbers 1, 2, 3,. . . , and 14. The printing sequence illustrated in FIG. 3B is the oneoccurring when face-down discharging is set in the image formingapparatus 200 as discharging a printed sheet to a tray. That is, imagesare arranged alternately on a first side on which an image is firstprinted and a second side being opposite to the first side.Specifically, on the first side, even-numbered pages are arranged indescending order, whereas on the second side, odd-numbered pages arearranged in ascending order. That is, for printing on the first side(printing on a sheet supplied from the upper sheet cassette 101 a or thelower sheet cassette 101 b), simplex printing and duplex printing haveopposite sequences of pages arranged (ascending order for simplexprinting and descending order for duplex printing). For printing on thesecond side of duplex printing (printing on a sheet supplied from thesheet winding unit 113), the sequence of pages is the same as that insimplex printing (ascending order). Accordingly, the sheets aredischarged face down in ascending order, as in the case of simplexprinting. Arrangement of pages for printing on both sides of a sheetvaries in response to the content of specified printing. That is, pagesmay be arranged differently from those illustrated in FIG. 3B. Forexample, if bookbinding printing is specified, the last page (here, page14) is arranged on the opposite side of page 1. A case where printing isspecified so as to exhibit arrangement illustrated in FIG. 3B isdescribed below as an example.

For normal duplex printing using cut sheets, in accordance with thesequence of inputted pages, images are printed in the sequence of page 1(on the first side), 2 (on the second side), 3 (on the first side), . .. , 13 (on the first side), and 14 (on the second side). However, forthe image forming apparatus 200, which employs a rolled sheet, ifprinting is performed in this sequence, it is necessary to cut a sheetafter an image is printed on the first side and, after winding the sheetand reversing the sheet, to print a next image on the second side. Theduplex printing way of completing printing for each sheet to bedischarged to a tray needs a long time. Accordingly, for the presentembodiment, the first side of a sheet for all of a series of pages issubjected to printing, and the sheet is then cut. The cut sheet iswound, the sheet is reversed, and images for the remaining second sidesare successively printed. Every time an image of one page is printed onthe second side, the sheet is cut for the one page. This can eliminatethe necessity of reversing a sheet every time an image is printed on asingle side of the sheet and thus can shorten the time required forprinting. That is, in response to a print job, the image formingapparatus 200 determines the sequence of printing images on sides of asheet so as to efficiently execute the print job in accordance with thecontent of the print job.

A procedure of a printing process occurring when printing is performedwith the foregoing arrangement is described below. FIG. 4 is a flowchartthat illustrates how the printing process performed by the image formingapparatus 200 proceeds. This flowchart illustrates a process performedby the CPU 201 loading a control program stored in the ROM 202 or theHDD 204 into the RAM 203 and executing the control program. Thisflowchart starts when the image forming apparatus 200 accepts a newprint job. It is assumed that the accepted print job is the one in whichspecification information to specify simplex printing with arrangementillustrated in FIG. 3A or duplex printing with arrangement illustratedin FIG. 3B and print data to be printed are received from the hostapparatus 211. For duplex printing with arrangement different from thatillustrated in FIG. 3B, images are successively printed on the firstside, and then, images are successively printed on the opposite side, asin the above-described way, except that the sequence of pages arrangedis different. For printing on odd-numbered pages or printing on only asingle side in part, there is a side on which an image has not beenprinted.

First, in S401, a print job is input from, for example, the hostapparatus 211. Print data contained in the input print job has aplurality of pages, and the data of the pages is input in succession inascending order from page 1. The CPU 201 temporarily stores this printdata in the HDD 204.

Next, in S402, it is determined whether the input print job is forsimplex printing or duplex printing. The determination is made based onwhether specification information contained in the print job indicatesprinting on only a single side or on both sides of a sheet. However, thedetermination may be made by various methods other than a method usingspecification information. For example, the determination may be made byanalyzing print data. If it is determined that simplex printing is to beperformed (NO in S402), flow proceeds to S403; if it is determined thatduplex printing is to be performed (YES in S402), flow proceeds to S405.

In S403, which corresponds to a case where only a single side is to besubjected to printing, because the arrangement illustrated in FIG. 3A isemployed, the CPU 201 determines that the printing sequence is the sameas the sequence of inputting images, i.e., in ascending order startingfrom page 1.

In S404, the CPU 201 supplies print data of each page to the imageprocessing unit 207 to perform printing in accordance with the printingsequence determined in S403. In response to this, the image processingunit 207 converts the print data into a form that allows the enginecontrol unit 208 to perform printing processing thereon (develops theprint data into image data) and stores the obtained image data in theHDD 204. The image processing unit 207 supplies the obtained image datato the engine control unit 208 in succession in accordance with theabove printing sequence. At this time, information indicating which sidethe image data is to be printed on and the page number and enabling theprint job to be identified is also provided together with the image datato the engine control unit 208.

The engine control unit 208 having received the image data supplies asheet corresponding to the size of an image to be printed from the uppersheet cassette 101 a or the lower sheet cassette 101 b. The enginecontrol unit 208 conveys the sheet using the conveying unit 102 to aprint position where the head unit 105 is to perform printing, printsimages based on the image data on the sheet in succession, and conveysthe sheet to a reading position where the scanner unit 107 is to performreading. Whether the images have been correctly printed is determinedbased on the content of the image data obtained by the scanner unit 107reading the formed images, and the sheet is conveyed toward the cutterunit 110. If it is determined that at least one of the images has beenincorrectly printed, the CPU 201 causes the cutter unit 110 to cut thesheet to discharge a page with the incorrectly formed image. The cutsheet corresponding to that page is discharged to a tray for use inreceiving defects (e.g., the lowermost tray) among the trays in thesorting unit 114. The CPU 201 supplies the image data to the enginecontrol unit 208 to reprint the unsuccessful image data and repeats thesubsequent above-described processing. If it is determined that theimages have been correctly printed, flow proceeds to S409.

In S405, which corresponds to a case where both sides are to besubjected to printing, because the arrangement illustrated in FIG. 3B isemployed, the CPU 201 determines that the printing sequence isdescending order starting from the last page of the even-numbered pagesfor the first side and ascending order starting from the first page ofthe odd-numbered pages for the second side. That is, to make pages be inseries on the same side of each of the first side and the second side,the printing sequence is page 14 (on the first side), 12 (on the firstside), . . . , 2 (on the first side), 1 (on the second side), 3 (on thesecond side), . . . , and 13 (on the second side). This printingsequence differs from the sequence of inputting print data (the sequenceof pages). The sequence of printing on the first side differs from theprinting sequence for simplex printing.

Then in S406, the CPU 201 supplies print data of each page to the imageprocessing unit 207 in the printing sequence determined in S405 toperform printing in accordance with the printing sequence determined inS405. In response to this, the image processing unit 207 converts theprint data for the first side into a form that allows the engine controlunit 208 to perform printing processing thereon (develops the print datainto image data) and stores the obtained image data in the HDD 204. Theimage processing unit 207 supplies the obtained image data to the enginecontrol unit 208 in the above page sequence. At this time, informationindicating which side the image data is to be printed on and the pagenumber and enabling the print job to be identified is also providedtogether with the image data to the engine control unit 208.

The engine control unit 208 having received the image data supplies asheet corresponding to the size of an image to be printed from the uppersheet cassette 101 a or the lower sheet cassette 101 b. The enginecontrol unit 208 conveys the sheet using the conveying unit 102 to aprint position where the head unit 105 is to perform printing, printsimages based on the image data on the first side of the sheet insuccession, and conveys the sheet to a reading position where thescanner unit 107 is to perform reading. Whether the images have beencorrectly printed is determined based on the content of the image dataobtained by the scanner unit 107 reading the formed images, and thesheet is conveyed toward the cutter unit 110. If it is determined thatthe images have been correctly printed, the sheet with the pages beingconnected together is caused to pass through the drying unit 112 withoutbeing cut on a page basis by the cutter unit 110. The sheet is subjectedto drying of ink and then is wound by the sheet winding unit 113. Incontrast, if it is determined that at least one of the images has beenincorrectly printed, the CPU 201 causes the cutter unit 110 to cut thesheet to discharge a page with the incorrectly formed image. The cutsheet corresponding to that page is discharged to a tray for use inreceiving defects (e.g., the lowermost tray) among the trays in thesorting unit 114. The CPU 201 supplies the image data to the enginecontrol unit 208 to reprint the unsuccessful image data and repeats thesubsequent above-described processing.

In the above-described way, when it is determined that the images of thepages specified to be printed on the first side have been correctlyprinted, flow proceeds to S407. In S407, the CPU 201 causes the cutterunit 110 to cut the sheet with the images formed on the first side atthe end of printing on the first side if needed. That is, in the case ofarrangement illustrated in FIG. 3B, the sheet is cut at a location ofthe end of printing the image of page 2 (with a margin if needed). Whenwinding the sheet by the sheet winding unit 113 has been completed, theprocess proceeds to printing on the second side. At this time, the imagedata for the first side remains in the HDD 204 to be ready for theoccurrence of poor printing on the second side.

Then in S408, the CPU 201 supplies print data of each page for thesecond side to the image processing unit 207 to perform printing on thesecond side in the printing sequence determined in the above way. Theimage processing unit 207 converts the print data for the second sideinto a form that allows the engine control unit 208 to perform printingprocessing thereon (develops the print data into image data) and storesthe obtained image data in the HDD 204. At this time, depending on thecontent of specification for printing, the image data may be rotated byapproximately 180°. The obtained image data is supplied to the enginecontrol unit 208 in the above page sequence. Also in this case,information indicating which side the image data is to be printed on andthe page number and enabling the print job to be identified is alsoprovided together with the image data to the engine control unit 208, asin the case of printing on the first side.

The engine control unit 208 conveys the sheet with the images formed onits first side wound in the sheet winding unit 113 to the conveying unit102 again, and images of the pages are printed on the second side insequence. For printing on the second side of the sheet, conveying thesheet from the sheet winding unit 113 starts such that an end at whichthe cutter unit 110 has cut is first conveyed and such that the sheet isreversed so as to make the second side face the head unit 105. When thesheet is conveyed to a print position where the head unit 105 is toperform printing, the engine control unit 208 prints images of pageswhose printing is specified at the back sides of corresponding images onthe first side in succession. The scanner unit 107 determines whetherprinting has been correctly performed, as in the case of printing on thefirst side. If poor printing occurs, the sheet is cut and the cutsection is discharged to a tray for receiving defects. For theoccurrence of poor printing, image data corresponding to the relevantpage is read from the HDD 204, and the first side and the second sideare subjected to printing again. Here, the details of reprinting imageson both sides are omitted. In this way, a plurality of images aresuccessively printed on the first side and, after completion of printingall images scheduled to be printed on the first side at a time, imagesto be arranged at the back sides of the images printed on the first sideare successively printed on the second side.

In S409, the sheet with the correctly formed images is cut on a pagebasis by the cutter unit 110. If the cut sheets have been determined tobe correctly printed, they are caused to pass through the drying unit112 while being subjected to drying of ink. Then the sheets are conveyedto the sorting unit 114 in succession and discharged to a specifiedtray. Depending on the number of pages printed in S404 and S408, theprocessing of S404 and S408 and the processing of S409 may be performedin synchronization with each other. If a tray is specified in a printjob, that tray is the destination to which the sheets are discharged. Ifno tray is specified, an empty tray is selected.

In the above-described way, determining the printing sequence for eachof simplex printing and duplex printing enables both simplex printingand duplex printing to discharge sheets face down and to, when aplurality of sheets are discharged, have the same sequence of the sheetsarranged. Accordingly, in collecting discharged sheets by a user,confusion caused by rearranging the sheets or by the coexistence offace-up discharging and face-down discharging can be avoided.

Although sheets are stacked on the small trays disposed in the uppersection of the sorting unit 114 with the sheets standing, the sheets arestacked in the correct sequence because pages are discharged from thesmallest page number in succession. Here, up to the maximum permissiblenumber of sheets for a tray, all the sheets are discharged to the sametray. This aims to discharge a print matter based on a single print job(order) to the same tray if possible. If a job exceeds the maximumpermissible number of sheets for a tray, sheets exceeding the maximumpermissible number are discharged to another tray. If a printed matterbased on a single print job is discharged to a plurality of trays, theLED on each of the plurality of trays emits beams with the same color.This enables a user to easily identify that printed matters dischargedto the plurality of trays are based on the single print job. Other thanthe use of the same color emission of LEDs, another method, such as theuse of displaying on the operating unit 206, can be employed innotifying a user that a single print job is output to a plurality oftrays.

In the above-described example, for both simplex printing and duplexprinting, sheets are discharged face down. Alternatively, for bothprinting, sheets may be discharged face up. In this case, for simplexprinting, the sheet winding unit 113 is employed, as in the case of theabove-described duplex printing. When face-up discharging is set in theimage forming apparatus 200, if simplex printing is specified, printingis performed in descending order from the last page and, even withsimplex printing, the sheet with the formed images is wound by the sheetwinding unit 113. At this time, the sheet is not cut on a page basis bythe cutter unit 110. The sheet is cut by the cutter unit 110 at the endof the sheet (at a location where printing the image on the first pagehas been completed), and the sheet is wound by the sheet winding unit113. After the completion of winding the sheet by the sheet winding unit113, the sheet is reversed and conveyed again. At this time, withoutprinting on the second side, the sheet is cut on a page basis by thecutter unit 110, and the cut sheets are discharged to a specified trayin the sorting unit 114. This enables the sheets to be discharged insequence from the last page face up for simplex printing.

To discharge sheets face up for duplex printing, the printing sequenceis that the odd-numbered pages are subjected to printing on the firstside in ascending order from the first page and the even-numbered pagesare subjected to printing on the second side in descending order fromthe last page in substantially the same way as for the above-describedduplex printing. With this, sheets can be discharged face up such thatthe sheets are stacked in succession from a sheet containing the lastpage to a sheet having a smaller page number. In this way, for bothsimplex printing and duplex printing, the sheets can be discharged faceup in the same sequence of pages arranged.

A user may select stacking sheets with formed images in succession froma small page number such that their discharge surfaces are placed facedown or, in contrast to this, stacking sheets with formed images insuccession such that a sheet having a smaller page number is dischargedlast and such that their discharge surfaces are placed face up, asdescribed above. In this case, either one can be specified by anoperation from a user through the operating unit 206 or the hostapparatus 211, the content of the specifying can be stored in the RAM203, and, in response to this, the CPU 201 can select a method ofdischarging sheets and the printing sequence. The method used indischarging sheets may be displayed on the operating unit 206 when theyare discharged. Alternatively, the image forming apparatus 200 maydischarge sheets only by either one method.

In the foregoing description, the cutter unit 110 cuts a sheet on a jobbasis or on a page basis. However, the sheet may be cut in another way.That is, the image forming apparatus 200 may not include the cutter unit110, and, for duplex printing, images are printed on the first sideuntil the sheet cassette becomes empty of the sheet and printing on theopposite side may be performed after the end of the sheet is used. Inthis case, a user may cut the sheet using another cutter device. It isnot necessary to continue printing on the first side until the cassettebecome empty of the sheet. For example, after a user cuts the sheetusing a cutter before the end of the sheet, a side to be subjected toprinting of the sheet may be changed, the sheet may be set again, andprinting on the second side may be performed.

In the foregoing example, for a case where a sheet is reversed, thesheet is wound by the sheet winding unit 113. However, the sheet maywait without being wound in a roll. That is, after images aresuccessively printed on the first side of a sheet, the sheet may wait(the sheet may be retained). In this case, any state of waiting or anyway of reversing the sheet may be employed as long as a reversingmechanism of reversing the sheet and allowing printing on the secondside to be performed is used. As previously described, a sheet that isnot subjected to printing on the first side may be reversed and thensubjected to printing on the second side.

In the foregoing description, processing of determining the printingsequence, other than printing processing, may be achieved by an externalapparatus, such as a host apparatus or an external controller, and inaccordance with this, the image forming apparatus may perform printing.In this case, the external apparatus obtains a status (informationindicating the occurrence of an error or the progress of printing) fromthe image forming apparatus and determines the printing sequence andarrangement of images. In this case, the external apparatus functions asthe print control apparatus.

The embodiments of the present invention can also be achieved byexecution of the following processing. That is, software (program) forachieving the functions of the above-described embodiments is suppliedto a system or an apparatus over a network or through various kinds ofstorage medium, and a computer (or CPU or MPU) of the system or theapparatus reads the program and executes it. The program may be executedby a single computer or by a plurality of computers working together.Not all of the above-described processing may be achieved by software.Part or all thereof may be achieved by hardware.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

What is claimed is:
 1. An apparatus capable of causing a print unit toprint data on a continuous sheet, the apparatus comprising: a receptionunit configured to receive data of a plurality of pages to be printed bythe print unit; a determination unit configured to determine whether thedata of the plurality of pages received by the reception unit is to beprinted on a single side of the continuous sheet or on both sides of thecontinuous sheet; and a print control unit configured to cause the printunit to print the data of the plurality of pages received by thereception unit on the continuous sheet in a manner such that anorientation of a front surface of each discharged sheet of duplexprinting from the continuous sheet in a case of being discharged afterhaving been printed on its both sides and an orientation of a frontsurface of each discharged sheet of simplex printing from the continuoussheet in a case of being discharged after having been printed on itssingle side is the same, wherein each discharged sheet of duplexprinting and of simplex printing have the front surface and a backsurface, wherein, in a case where the determination unit determines thatsimplex printing is to be performed, the print control unit causes theprint unit to print each page to be arranged on the front surface of adischarged sheet of simplex printing first, and wherein, in a case wherethe determination unit determines that duplex printing is to beperformed, the print control unit causes the print unit to print eachpage to be arranged on the back surface of a discharged sheet of duplexprinting first.
 2. The apparatus according to claim 1, wherein the printcontrol unit is configured to cause the print unit to print the data ina manner such that a sheet on which a first page image of a firstodd-numbered page in the data is printed is discharged in a state wherethe first page image faces upward.
 3. The apparatus according to claim2, wherein the print control unit is configured to cause the print unitto print the data in a manner such that discharged sheets are arrangedin ascending order.
 4. The apparatus according to claim 1, wherein theprint control unit is configured to cause the print unit to print thedata in a manner such that a sheet on which a first page image of afirst odd-numbered page in the data is printed is discharged in a statewhere the first page image faces downward.
 5. The apparatus according toclaim 4, wherein the print control unit is configured to cause the printunit to print the data in a manner such that discharged sheets arearranged in descending order.
 6. The apparatus according to claim 1,further comprising a cutting unit configured to cut the continuous sheetprinted by the print unit into cut sheets by controlling a cutter. 7.The apparatus according to claim 6, wherein, in a case where thedetermination unit determines that the data is to be printed on thesingle side of the continuous sheet, the cutting unit cuts the printedcontinuous sheet based on a predetermined unit, and wherein, in a casewhere the determination unit determines that the data is to be printedon both sides of the continuous sheet, the cutting unit does not cut thecontinuous sheet based on the predetermined unit during printing on afirst side of the continuous sheet and cuts the continuous sheet basedon the predetermined unit during printing on a second side of thecontinuous sheet.
 8. The apparatus according to claim 7, wherein, in acase where the determination unit determines that the data is to beprinted on both sides of the continuous sheet, the cutting unit cuts thecontinuous sheet at an end of printing on the first side of thecontinuous sheet after completion of printing the data of pages to bearranged on the first side of the continuous sheet.
 9. The apparatusaccording to claim 6, further comprising a sorting control unitconfigured to control receiving of the discharged cut sheets by a trayin a sorting unit.
 10. The apparatus according to claim 1, wherein, in acase where the determination unit determines that the data is to beprinted on both sides of the continuous sheet, the print control unitcauses the print unit to successively print data of pages to be arrangedon a first side of the continuous sheet among the data of the pluralityof pages received by the reception unit and then to print data of pagesto be arranged on a second side of the continuous sheet.
 11. Theapparatus according to claim 1, further comprising a selecting unitconfigured to select a discharging method for a discharge unit from oneof a face-up discharging method and a face-down discharging method,wherein the print control unit reverses an arranged order of pages inprinting by the print unit depending on whether the selecting unitselects the face-up discharging method or the face-down dischargingmethod.
 12. The apparatus according to claim 1, further comprising theprint unit.
 13. A method for an apparatus capable of causing a printunit to print data on a continuous sheet, the method comprising:receiving data of a plurality of pages to be printed by the print unit;determining whether the received data of the plurality of pages is to beprinted on a single side of the continuous sheet or on both sides of thecontinuous sheet; and causing the print unit to print the received dataof the plurality of pages on the continuous sheet in a manner such thatan orientation of a front surface of each discharged sheet of duplexprinting from the continuous sheet in a case of being discharged afterhaving been printed on its both sides and an orientation of a frontsurface of each discharged sheet of simplex printing from the continuoussheet in a case of being discharged after having been printed on itssingle side is the same, wherein each discharged sheet of duplexprinting and of simplex printing have the front surface and a backsurface, wherein, in a case where it is determined that simplex printingis to be performed, causing includes causing the print unit to printeach page to be arranged on the front surface of a discharged sheet ofsimplex printing first, and wherein, in a case where it is determinedthat duplex printing is to be performed, causing includes causing theprint unit to print each page to be arranged on the back surface of adischarged sheet of duplex printing first.
 14. The method according toclaim 13, wherein causing includes causing the print unit to print thedata in a manner such that a sheet on which a first page image of afirst odd-numbered page in the data is printed is discharged in a statewhere the first page image faces upward.
 15. The method according toclaim 14, wherein causing includes causing the print unit to print thedata in a manner such that discharged sheets are arranged in ascendingorder.
 16. The method according to claim 13, wherein causing includescausing the print unit to print the data in a manner such that a sheeton which a first page image of a first odd-numbered page in the data isprinted is discharged in a state where the first page image facesdownward.
 17. The method according to claim 16, wherein causing includescausing the print unit to print the data in a manner such thatdischarged sheets are arranged in descending order.
 18. A non-transitorycomputer-readable storage medium storing a program to cause anapparatus, capable of causing a print unit to print data on a continuoussheet, to perform a method, the method comprising: receiving data of aplurality of pages to be printed by the print unit; determining whetherthe received data of the plurality of pages is to be printed on a singleside of the continuous sheet or on both sides of the continuous sheet;and causing the print unit to print the received data of the pluralityof pages on the continuous sheet in a manner such that an orientation ofa front surface of each discharged sheet of duplex printing from thecontinuous sheet in a case of being discharged after having been printedon its both sides and an orientation of a front surface of eachdischarged sheet of simplex printing from the continuous sheet in a caseof being discharged after having been printed on its single side is thesame, wherein each discharged sheet of duplex printing and of simplexprinting have the front surface and a back surface, wherein, in a casewhere it is determined that simplex printing is to be performed, causingincludes causing the print unit to print each page to be arranged on thefront surface of a discharged sheet of simplex printing first, andwherein, in a case where it is determined that duplex printing is to beperformed, causing includes causing the print unit to print each page tobe arranged on the back surface of a discharged sheet of duplex printingfirst.